The invention generally relates to containers for combustible liquids and more specifically relates to a combination safety storage tank and fire extinguisher which is constructed so that the explosion hazards inherent in the design of a storage tank are eliminated allowing the storage tank to be used in an automobile, airplane, motor boat, or other moving vehicle or simply as a storage device.
The safety storage tank is normally used for the storing of volatile fuels such as gasoline. In ordinary conditions of the storage of gasoline, air usually enters the tank as the gasoline is removed from the tank. Under such conditions the upper part of the partially filled tank contains a dangerous explosive mixture of gasoline vapor and air. If a spark occurs in the upper part of the tank through an electrical discharge of static electricity or from contact with other structures, fire and explosion will result.
The present invention eliminates this explosive hazard by unique construction of the tank in that the air is replaced in the space above the gasoline by an inert gas such as carbon dioxide which is heavier than air and which will not form an explosive mixture with the gasoline. The carbon dioxide is pressurized and attached to the tank so that it automatically replaces the gasoline as the gasoline is discharged from the tank.
The invention is also provided with a release valve which will allow excess pressure and air from inside the tank to escape. A pressure indicating gauge is connected to the release valve or to the tank to indicate to the operator or owner of the tank the current pressure in the tank. The invention also has the dual function as a fire extinguisher as the pressurized carbon dioxide is also used to expell an inert foam held in the tank.